Semiconductor device including transistor and method of manufacturing the same
A semiconductor device includes a gate pattern disposed on a semiconductor substrate, a bulk epitaxial pattern disposed in a recess region formed in the semiconductor substrate at a side of the gate pattern, an insert epitaxial pattern disposed on the bulk epitaxial pattern, and a capping epitaxial pattern disposed on the insert epitaxial pattern. The bulk epitaxial pattern has an upper inclined surface that is a {111} crystal plane, and the insert epitaxial pattern includes a specific element that promotes the growth rate of the insert epitaxial pattern on the upper inclined surface.
1. A semiconductor device comprising:
a gate pattern disposed on a semiconductor substrate with a recess region formed in the semiconductor substrate at a side of the gate pattern;
a bulk epitaxial pattern disposed in the recess region, the bulk epitaxial pattern having an upper inclined surface that is a {111} crystal plane of the bulk epitaxial pattern;
an insert epitaxial pattern disposed on the bulk epitaxial pattern, the insert epitaxial pattern including a specific element that promotes a growth rate of the insert epitaxial pattern on the upper inclined surface; and
a capping epitaxial pattern disposed on the insert epitaxial pattern.
2. The semiconductor device of claim 1 , wherein the semiconductor substrate is formed of a first semiconductor element,
wherein the bulk epitaxial pattern includes a second semiconductor element different from the first semiconductor element,
wherein the specific element of the insert epitaxial pattern is the second semiconductor element, and
wherein a concentration of the second semiconductor element in the insert epitaxial pattern is lower than a concentration of the second semiconductor element in the bulk epitaxial pattern.
3. The semiconductor device of claim 2 , wherein the second semiconductor element has an atomic diameter that is different from an atomic diameter of the first semiconductor element.
4. The semiconductor device of claim 2 , wherein the capping epitaxial pattern is formed of the first semiconductor element.
5. The semiconductor device of claim 1 , wherein the recess region includes an undercut region tapered toward a channel region under the gate pattern, and
wherein inner surfaces of the recess region constituting the tapered undercut region are included in {111} crystal planes of the semiconductor substrate.
6. The semiconductor device of claim 1 , further comprising:
a device isolation pattern formed in or on the semiconductor substrate and defining an active portion,
wherein the gate pattern is disposed on the active portion,
wherein the recess region is formed in the active portion at a side of the gate pattern, and
wherein a bottom end of the upper inclined surface of the bulk epitaxial pattern is adjacent to the device isolation pattern.
7. The semiconductor device of claim 1 , wherein the bulk epitaxial pattern provides a stress to a channel region under the gate pattern.
8. A semiconductor device comprising:
a semiconductor substrate including a first semiconductor element;
a device isolation pattern that defines an active semiconductor portion of the semiconductor substrate
a gate pattern including a gate electrode mounted on the active portion of the semiconductor substrate and covering a channel region in the active portion of the semiconductor substrate;
at least one recess region defined in the active portion of the semiconductor substrate between the gate pattern and the device isolation pattern;
a bulk epitaxial pattern formed in the recess region, including an upper surface inclined along a {111} crystal plane, and providing a stress to the channel region;
an insert epitaxial pattern formed on the bulk epitaxial pattern and including a second semiconductor element that desorbs hydrogen from the upper inclined surface of the bulk epitaxial pattern; and
a capping epitaxial pattern formed on the insert epitaxial pattern.
9. The semiconductor device of claim 8 , wherein the second semiconductor element is germanium.
10. The semiconductor device of claim 9 , wherein the first semiconductor element is silicon.
11. The semiconductor device of claim 10 , wherein the capping epitaxial pattern includes silicon.
12. The semiconductor device of claim 10 , further comprising:
an ohmic pattern formed of a metal silicide on the capping epitaxial pattern;
an interlayer insulating layer formed on the ohmic pattern and on the gate pattern;
an interconnection formed of an electrically conductive pattern on the interlayer insulating layer; and
a contact plug formed of an electrically conductive material passing through the interlayer insulating layer and connecting the interconnection and the ohmic pattern.